European Patent No. 1 376 051 B1 describes the calibration of an image sensor system on a motor vehicle using a calibration object and a position reference sensor. The method described there for calibrating an image sensor system, which is preferably located on a motor vehicle, uses at least one test image, the image sensor system taking the test field, and the test field taken being used for the calibration; the test field having calibration reference features having a known spatial geometric system and the image sensor system taking the calibration reference features.
German Published Patent Appln. No. 199 62 997 A1 describes a method for calibrating a sensor system, using which the recording and evaluation of objects in the track routing of a vehicle is described. In this method, characteristic data of the objects are recorded and the data, which are interpreted as stationary or quasi-stationary objects, taking into account the vehicle's own motion, are sent to a calibration unit. The deviations in the data measured currently from data provided by a model of the objects are ascertained as an error vector in the calibration unit and used to correct the data of the model for the purpose of minimizing the deviation.
German Patent No. 198 15 106 B4 describes a method for measuring camera properties and lens properties for camera tracking, at least one virtual object being positioned in it relative to at least one actual object in combined images of an actual surroundings and virtual surroundings including the steps that the palpation settings of the camera and the lens are selected, that the real environment is photographed by the camera and the lens and a first video signal, which represents the real environment, is transmitted to a common display device, the real environment including at least one real scale.
Fixed-focus lenses have a fixed focus that have an unchangeable distance setting. It is a well-known approach to focus cameras with fixed-focus lenses on the so-called hyperfocal distance. Such focusing is distinguished in that the depth of the field range is between infinity and one-half the hyperfocal distance. The hyperfocal distance is calculated from the focal length of the lens used in the camera, the diameter of the acceptable circle of confusion in the image plane and the f-number. Typical values of the hyperfocal distance for automotive cameras are in the range between 4 m and 11 m. Such distances cannot be implemented meaningfully in a test device in the production environment.